Fluid pressure system



Feb. 13,1940. H. c; ower-.19 2,190,228

FLUID PRESSURE SYSTEM Fiied Sept. 7, 1937 2 Sfieet-Sheet 1 a0 /0a 74 76 w /a 62 44 98 INVENT OR.

A'ILLORNEY H. c. BOWEN FLUID PRESSURE SYSTEM Feb; 13, 1940.

2 Sheets-Sheet 2 Filed Sept. 7, 1957 l-llllt INVENTOR. his-Eater CZ Bows/v BY Z ATTORNEY atented Feb. 13, I V l FLUID PRESSURE SYSTEM i ll'erbert 0. Bowen, Detroit, Mich, minor to Hydraulic Brake Company, Detroit, Mich, a

corporation California I J 1 Application September '1. 1937, Serial No. 162,787

' comm (i. cit-54.6),

Thisinvention relates toiiuid pressure-systems A casing 22 suitably secured to the housing Broadly the invention comprehends asimple oi the differential H has mounted therein a and efiiclent fluid pressure system for actuating rotatable shaft 24, and a sleeve 26 keyedon the a planetary transmission. In a preferred emshaft has formed integral therewith a fork 28 ibodiinent of the invention,aduplex fluid pressure embracing the shiftable-gear and a lever 30 5;

producing device has connected thereto opposed havingispaced recesses 32 arranged therein'adjafluid pressure actuated motors and a lever for cent its free end for the reception ofa spring-i actuating the shiftable element or a planetary pressed plunger 34 for retaining the lever, and, transmission is connected between the motors; accordingly. h fork 28 and gcarjmjfi'n either v m The duplex fluid pressure producing device is one or two positions; The shaft also has suitably 10 t operativeto selectively energize the motors so secured thereto; outside of the as man b r that the lever may be moved to either oftwo sting lever 36. L I it positions so as to effectively shift the gears of the A fl id P e Pr i evi e indic t d transmission.

I Uniau STATES. PATE V v p generally at 38 issuitably mounted on theirame is An object ot'the inventionis to provide a fluid I 0. This device includes a' reservoir 40 having lr (pre sure system having but few parts, arranged in at its base corresponding cylinders 42 and 44 compact form, and so connected to the shifting arranged in axial alignment w r pect to o iever of a planetary transmission as to insure an th ran diametrically of e ervo riwi h positive actuation of the transmission. oppositely disposed endsopenine directly into; Another object 01' the invention is to provide t reservoir- The Outer ends of the de s a duplex fluid pressure producing device having 42 and are 1 5M e-sj heads 45 n 4 Pro.- a connected thereto opposed fluid pressure actuated Vided W discharge: DO S nd 52 c ntrolled motors connected respectively to the shitting lever" as by w -W y v lves and 5B. it 1 1 i of a planetary transmission. V a The discharseports 50 and l are connected A further object or the invention is toprovide by fluid pressure delivery ipes Or o du ts 58 an efllcient duplex fluid pressure producing deand to fluid p su actuated meters 6 n vice of marked simplicity a a whole a 64 arranged forthe "actuation of the lever '36; respect to each of'its component parts'so that s h w e flt e vs eur d on the its manufacture may be economically facilitated e e 22 p r s the m r in mw t r it both as regards parts and their assembly. Posed relation b e e et and us P 80- Other objects and advantages of the invention end connect th P n of the respective will appear from the following description taken motors to the e 5- i i in connection w1th the drawings fglmfl g a part Adouble-hea'ded piston 12 reciprocable in the of the specification; and i whjch cylinders 42 and 44'; includes a hollow cylindrical i v 5 Fig. 1-1 a'top plan view 1 smotor which body 14 having a diameter slightly less than that 35 chassis, partly broken away, illu tratin th i of the cylinders, providing, in conjunction with t vention as applied;

y i a the walls of the respective cylinders, an annular Fig. 2 is a vertical sectional view oi the fluid Passage n ne. with the reservoir; pregsure'prgdugmg i I I and arranged in the wall ;of the body portion 40 Fig 3 1s a fragmentary View of an t t is a slot", providing a communication between 40 and fluid pressure actuated motorsfor operating t reservoir and the e r of the body "a i the actuator, the motors being shown in section; Corresponding heads 99 and 82 detachably and I secured to the respective ends of the body 14 have Fig 4 is a fragmentary view"gf twosspeed axialports 84 and 86 providing communications as axle, the transmission thereof, and thefluid presbetween the interior ithe (body H and those 45 sure t t motors v portions of the cylinders "and 44 forward of Refemng t t drawings for o specifi the heads. The heads also have spaced peripheral details of the invention, ill represents a motor 610175 83 and Pmvidmgcommunicafions vehicle chassis frame supported on springs t tween those portions of the cylinders forward 01" 5c shown, suspended from a front axle, also not h h n the annular P a e i I shown; and a. rear axlelz having a diflerential Coll psi l i lips 92 nd 94 seated on it. The axle l2 has mouiitedthereon for rotathe respective heads and 82 01' the piston ticn wheels l6 of conventional type, and a twocontrol the, passages 88 and 90, and springs 96 speed transmission I8 including a shiftable gear and 98 interposed between the respective cups 55 29 is associated with the diflerential. and the two-way valves 64 and 66 serve to retain 55 *1 the cups and valves against displacement. The

for reciprocation in the body of the piston, are arranged in oppositely disposed relation to one another. As shown, the plungers include shells I08 and IIO having peripheral slots II2 and II4 providing passages through the shells. The plungers have heads ,II8 and H8 adapted to engage the backs of the heads of the respective pistons when the plungers are in advanced position, and arranged concentrically on the heads H8 and 8 are projections I20 and I22 adapted to enter the ports 84 and 86 and engage the sealing cups 92 and 94 so as to effectively seal the ports.

Corresponding pressure blocks I24 and I26 reciprocable in the shells I08 and I I0 have passages I28 and I30 in their perimeters providing communications between the passages H2 and H4 and the interior of the piston. The blocks also have recesses for the reception of springs I32 and I34 interposed between the blocks and the plungers.

A shaft I36 arranged transversely of the reservoir 40 has mounted thereon, within the reservoir, an operating lever I38. The lower end I 40 of this lever is interposed between the pressure blocks I 24 and I26, and a flexible cup I42 sleeved on the lever embraces the open end of the reservoir so as toexclude dust and other foreign substances from the reservoir. A spring I44 wound on the shaft has its respective ends engaging the wall ofthe reservoir and projecting into the slot I8 in the body of the piston. This spring serves to return the piston to its position of rest and to center the piston. V g

In a normal operation, uponactuatingthe operating lever I38, force is transmitted therefrom to the piston I2, resulting in movement of the piston in either one of two directions. Assuming that the operating lever I38 is moved backwardly, under this condition, the piston 12 .is moved forwardly against the. resistance of the spring I44. During the initial movement of the piston, the force applied thereto is'received by the pressure block I24 of the expansible plunger I04, resulting in compression of the spring I32, and thereafter-the plunger I04 moves as a single unit.

The plunger bears against the back of the head 80 of the piston and the projection I20 on the plunger rests in the port 84 in the head 80 of the piston, in engagement with the inner perimeter of the cup 92. Accordingly, upon further movement of the piston, fluid is displaced from the cylinder 42 past the valve 54 through the discharge port and the fluid pressure delivery pipe 58 into the fluid pressure actuated motor 62, causing energization of the motor. This results in rocking the shaft 24 and the fork 28 carried by the shaft, and this movement of the fork moves the gear 20 to shift the transmission to the low speed position.

During this operation the head 82 of the piston recedes, and a partial vacuum is created in that portion of the cylinder 44 forward of the head 82. This results in drawing fluid from the reservoir, through the annular passage I6, the passages 90 in the head 82, and past the cup 94 on the head, into that portion of the cylinder 44 forward of the head, completely filling the cylinder.

Now, upon releasing the lever I38, the spring I44 returns the piston to its retracted or neutral position, and as the piston returns to its retracted position the pressure on the fluid in the cylinder 44 is received on the expansible plunger I06, and this results in compressing the plunger and thereby opening the port 86 in the. head 82 and establishing communication between the reservoir and that portion of the cylinder 44 forward of the head 82; and simultaneously therewith the head of the piston recedes, resulting in the creation of a partial vacuum in that portion of the cylinder 42 forward of the head 80, resulting in drawing fluid from the reservoir through the annular passage 16, the passages 88 in the head 80, past the cup 82, into that portion of the cylinder 42 forward of the head 80, completely filling the cylinder 42. When the piston is in fully retracted position, both of the cylinders 42 and 44 are completely filled with fluid under pressure equal to the load on the springs I32 and I34 of the respective expansible plungers I04 and I06.

Although this invention has been described in connection with certain specific embodiments, the principles involved are susceptible of numerous other applications that will readily occur to persons skilled in the art. The invention is, therefore, to be limited only by the scope of the appended claims.

Having thus described the various features of the invention, what I claim as new and desire to secure by Letters Patent is- 1. A fluid pressure producing device comprising a reservoir, opposed cylinders opening into the reservoir, a piston reciprocable in the cylinders including a hollow cylindrical slotted body' having an oriflced head on each end thereof, opposed expansibleplungers movable in the cylindrical body for cooperation with the orificed heads, and

, a lever for actuating the plungers having a part extended-through the slot and interposed between the plungers.

2. A fluid pressure producing device comprising a reservoir, opposed cylinders opening into the reservoir, heads on the outer ends of cylinders having discharge ports, a piston reciprocable in the cylinders including a hollow cylindrical slotted body having an oriflced head on each end thereof, opposed expansible plungers movable in the body for cooperation with the orificed heads, an actuator. having a part extended through the slot and interposed between the plungers, and means for simultaneously returning the piston and actuator to neutral position.

3. A fluid pressure producing device comprising a'reservoir, opposed cylinders opening into the reservoir, a piston reciprocable in the cylinders including a hollow cylindrical body having a slot therein, an orificed-head on each end of the piston, opposed expansible plungers reciprocable in the cylinders for cooperation with the orificed heads, a shaft in the reservoir, an actuator rockable on the shaft having a part engaging the plungers, and a spring on the shaft having its respective ends projecting into the slot in the body of the piston.

4. A fluid pressure producing device comprising a reservoir, opposed cylindersopening into the reservoir, a piston reciprocable in the cylinders including a hollow cylindrical body of smaller diameter than that of the cylinders having a centralized slot, an orificed head on each end of the piston having spaced passages therethrougn, opposed expansible plungers reciprocable in the piston for cooperation with the orifices in the till lid

the slot in the piston.

6. In a fluid pressure system, a fluid pressure heads, a shaft mounted transversely of the reservcir, an actuator on the shaft having a part engaging the plunger, and a spring wound on the shaft having its respective ends extended into 5. A fluid pressure producing device comprising a reservoir, opposed cylinders opening into the reservoir, a head on each of the cylinders having a discharge port, valves controlling the discharge ports, a piston reciprocable in the cylinders including a cylindrical body of smaller diameter than that of the cylinders having a centralized slot, an orificed head on each end of the piston having spaced peripheral passages therethrough, sealing cups on the heads of the piston controlling the passages and overhanging the orifices, opposed expansible plungers reciprocable in the piston for cooperation with the orifices in the heads, a shaft mounted transversely of the reser-v voir, an actuator rockable on theshaft having a part interposed between and engaging the plungers, and a spring wound on the shaft having its respective ends normally engaging the wall of the reservoir and projecting therefrom into the slot in the piston.

producingdevice comprising a reservoir, opposed cylinders opening into the reservoir. a head on each cylinder having a discharge port, valves controlling the discharge ports, a fluid pressure actuated motor connected to each of the discharge ports, a rockable member connected to the motors, a piston reciprocable in the cylinders including a cylindrical body of smaller diameter than that of the cylinders having a centralized slot, a head on each end of the piston having an axial orifice and peripheral passages therereservoir and extending therefrom into the slot in the piston.

HERBERT C. BOWEN. 

